Paying a gym once a month to use their treadmills (aka moving sidewalks) and workout machines doused in other men's sweat is a waste. Mother Nature and your local government teamed up awhile ago to provide you with all of the exercise equipment you need. There's a park and some sidewalks in your neighborhood—start running. Cardio? Check. The flashing crosswalk lights are extremely effective for pull-ups, so that takes care of your upper body work out. Use the stairs instead of the elevator and feel the burn in your legs. Need more guidance and think a personal trainer will help? YouTube is the answer. See? Total body workout for free-99.